1. Field of the Invention
The present invention relates to data collection and processing systems, and more particularly, to portable data terminals having a system for controlling speaker volume to compensate for varying ambient noise environments.
2. Description of Related Art
Portable data collection terminals are well known in the art for remote data collection applications such as inventory control, manufacturing and production flow management, and asset tracking. A mobile worker may use such a data collection terminal to collect, send and receive information while moving throughout a work area. The data collection terminal may either comprise a specialized device or a general purpose laptop computer or personal digital assistant (PDA) adapted for use in the particular application. Portable data collection terminals are also commonly used by sales persons, distributors, delivery persons, auditors, and the like, where it is advantageous to employ a portable data terminal in a route or otherwise mobile setting. Such applications include sales, distribution, control and inventory of products delivered, and delivery or tracking of products, packages, etc.
Portable data collection terminals typically include apparatus to facilitate efficient input and manipulation of data by a user. For example, a data collection terminal may include such apparatus as keypads, touch screens, laser scanners, optical indicia readers, and the like. Preferably, such apparatus allow the data collection terminal to read and manipulate data recorded in a variety of mediums and in many different formats. The data collection terminals often also include an audio output device, such as a speaker, to emit sounds in response to certain actions taken or functions performed. For example, it is known for a data collection terminal to emit a certain tones or beeps signifying that data (e.g., a bar code symbol) was faithfully collected by the terminal. Other sounds may be emitted for other purposes, such as to reflect failure to read the bar code symbol, entry of an improper key, receipt of an email message, rebooting of the terminal, and the like. The operator of the collection terminal may come to rely upon the audible feedback to ensure that data has been properly entered.
A drawback of these known audible feedback systems is that the data collection terminal is often used in work environments having varying levels of ambient noise. In a particularly loud work environment, such as on a factory floor, it may be difficult for the operator to hear the audible feedback over the ambient noise. To compensate, the operator may turn up the volume of the audible feedback, such as by adjusting a knob or manipulating a screen icon using a pointing device. When the operator exits the noisy environment and enters a quieter environment, such as a storage area or office floor, the operator must remember to turn back down the volume to prevent the amplified audible feedback from disturbing workers in that environment. As a result, the operator often finds that the volume must be continuously adjusted in correspondence with changes from one work environment to another.
Accordingly, it would be desirable to provide a data collection terminal in which the audible feedback volume does not need to be changed as the operator moves between different ambient noise environments.